Slow flash (blue, normally off, flashes on) — Ignition lockout

What does Slow flash (off to on) mean?

The boiler's blue indicator light flashes slowly from off to on, indicating an ignition lockout. This means the boiler failed to ignite the gas.

• No gas supply or low gas pressure
• Problems with the flue system
• Faulty ignition electrodes or their connections
• Faulty flame sense electrode or its connections
• Malfunctioning gas valve

Click steps to track your progress.

1. 1

   Reset the boiler using the user control panel, usually by pressing a dedicated reset button.

2. 2

   Check that your main gas supply valve to the property and boiler is fully open.

3. 3

   Verify other gas appliances (e.g., gas hob) are working to confirm gas supply is present and at correct pressure.

4. 4

   If the boiler still fails to ignite, contact a qualified service engineer as this may indicate a combustion component issue.